We talked to Prager about this provocative new book and the surprises she found during her research.

1. How did you land on the title for your book?

Originally I was going to focus on wacky creatures as a hook—and why they matter to society. In talking to colleagues and digging into academic journals, however, three very enticing and consistent themes emerged. First, slime: Many animals in the ocean use mucous in some form, maybe for defense or as a net to catch food or to travel faster. Second, sex: Many strange behaviors have evolved over millions of years so organisms can reproduce successfully in the ocean.

And finally, I didn’t realize the breadth and diversity of marine life used in the search for new drugs or as models for biomedical research until I did the research for the book. So I revised the title.

2. From the cuttlefish and orgies of 40,000 participants to the self-martyrdom of the male blanket octopus in the name of love, which creature from the book is your nominee for most surprising sex partner in the sea?

It’s hard to choose just one! Take the anglerfish, where the males are much smaller than females. The whole mission of a male’s life seems to be to search out and find a female for an everlasting kiss. Basically, he bites onto her body, fuses to her and becomes a sperm-producing parasite.

3. With all of your expertise, did anything surprise you in the course of your

Lots! Like the fact that there is so much we just don’t know. We are still discovering many creatures for the first time—and even for those we’ve previously identified, there is still much to learn. For instance, scientist Roger Hanlon has long been working on cephalopods and camouflage. He and his colleagues discovered that octopuses and squid are colorblind, so how exactly do they have this incredible ability to change color to match their surroundings? He suspects they have color sensors in their skin, but has yet to figure it out. There are many fascinating stories like that.

4. You explain so many benefits we gain from ocean life; which are foremost in your mind these days?

I would say two, and the first is food. Several billion people across the world rely on the ocean for a major source of the protein in their diet. And we have more and more people on Earth. The ocean is not going to be able to sustain the demand. I worry about overfishing and also the human health crisis that could occur if we continue to overfish our oceans.

Secondly, most people don’t know that the ocean is the frontier for the discovery of new pharmaceuticals that fight all sorts of diseases. And ocean life helps us understand human physiology. I was really struck when researching the book that almost every ocean environment has some creature being looked at for biomedical or biotech benefits.

5. Is there one particular threat to the denizens of the deep that you wish more people knew about?

I can’t say there’s a ”worst”; for me, there’s a “top five.” Number one is climate change. The issue of accelerated seawater-warming and ocean acidification together is a double whammy. The others are pollution, overfishing, habitat loss and invasive species. For the big picture, we need to work on climate change. Locally, I think marine debris, pollution and overfishing are really important.

6. Would you share three ways we can help protect the sea’s oddest creatures—and all the others?

Be a voice for the ocean. That means contact your political representatives at the local, state or national level and tell them to do more to protect the ocean.